I kept a favia and red lobo under 96 watt pcs in my ten gallon. That's only 12" deep and they were on the bottom, some favias would do fine I would think and can be placed in the rockwork but I would hold off on a lobo since they like sandbeds better, unless you have a good spot to place one where it won't expand into the rocks at all. Don't know about trachys but a red one would be better to try than green as they need less light.